tag-utils.h

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/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2023 Wim Taymans */
/* SPDX-License-Identifier: MIT */
 
#ifndef SPA_PARAM_TAG_UTILS_H
#define SPA_PARAM_TAG_UTILS_H
 
#include <float.h>
 
#include <spa/utils/dict.h>
#include <spa/pod/builder.h>
#include <spa/pod/iter.h>
#include <spa/pod/parser.h>
#include <spa/param/tag.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifndef SPA_API_TAG_UTILS
 #ifdef SPA_API_IMPL
  #define SPA_API_TAG_UTILS SPA_API_IMPL
 #else
  #define SPA_API_TAG_UTILS static inline
 #endif
#endif
 
SPA_API_TAG_UTILS int
spa_tag_compare(const struct spa_pod *a, const struct spa_pod *b)
{
        return ((a == b) || (a && b && SPA_POD_SIZE(a) == SPA_POD_SIZE(b) &&
            memcmp(a, b, SPA_POD_SIZE(b)) == 0)) ? 0 : 1;
}
 
SPA_API_TAG_UTILS int
spa_tag_parse(const struct spa_pod *tag, struct spa_tag_info *info, void **state)
{
        int res;
        const struct spa_pod_object *obj = (const struct spa_pod_object*)tag;
        const struct spa_pod_prop *first, *start, *cur;
 
        spa_zero(*info);
 
        if ((res = spa_pod_parse_object(tag,
                        SPA_TYPE_OBJECT_ParamTag, NULL,
                        SPA_PARAM_TAG_direction, SPA_POD_Id(&info->direction))) < 0)
                return res;
 
        first = spa_pod_prop_first(&obj->body);
        start = *state ? spa_pod_prop_next((struct spa_pod_prop*)*state) : first;
 
        res = 0;
        for (cur = start; spa_pod_prop_is_inside(&obj->body, obj->pod.size, cur);
             cur = spa_pod_prop_next(cur)) {
                if (cur->key == SPA_PARAM_TAG_info) {
                        info->info = &cur->value;
                        *state = (void*)cur;
                        return 1;
                }
        }
        return 0;
}
 
SPA_API_TAG_UTILS int
spa_tag_info_parse(const struct spa_tag_info *info, struct spa_dict *dict, struct spa_dict_item *items)
{
        struct spa_pod_parser prs;
        uint32_t n, n_items;
        const char *key, *value;
        struct spa_pod_frame f[1];
 
        spa_pod_parser_pod(&prs, info->info);
        if (spa_pod_parser_push_struct(&prs, &f[0]) < 0 ||
            spa_pod_parser_get_int(&prs, (int32_t*)&n_items) < 0)
                return -EINVAL;
 
        if (items == NULL) {
                dict->n_items = n_items;
                return 0;
        }
        n_items = SPA_MIN(dict->n_items, n_items);
 
        for (n = 0; n < n_items; n++) {
                if (spa_pod_parser_get(&prs,
                                SPA_POD_String(&key),
                                SPA_POD_String(&value),
                                NULL) < 0)
                        break;
                if (key == NULL || value == NULL)
                        return -EINVAL;
                items[n].key = key;
                items[n].value = value;
        }
        dict->items = items;
        spa_pod_parser_pop(&prs, &f[0]);
        return 0;
}
 
SPA_API_TAG_UTILS void
spa_tag_build_start(struct spa_pod_builder *builder, struct spa_pod_frame *f,
                uint32_t id, enum spa_direction direction)
{
        spa_pod_builder_push_object(builder, f, SPA_TYPE_OBJECT_ParamTag, id);
        spa_pod_builder_add(builder,
                        SPA_PARAM_TAG_direction, SPA_POD_Id(direction),
                        0);
}
 
SPA_API_TAG_UTILS void
spa_tag_build_add_info(struct spa_pod_builder *builder, const struct spa_pod *info)
{
        spa_pod_builder_add(builder,
                        SPA_PARAM_TAG_info, SPA_POD_Pod(info),
                        0);
}
 
SPA_API_TAG_UTILS void
spa_tag_build_add_dict(struct spa_pod_builder *builder, const struct spa_dict *dict)
{
        uint32_t i, n_items;
        struct spa_pod_frame f;
 
        n_items = dict ? dict->n_items : 0;
 
        spa_pod_builder_prop(builder, SPA_PARAM_TAG_info, SPA_POD_PROP_FLAG_HINT_DICT);
        spa_pod_builder_push_struct(builder, &f);
        spa_pod_builder_int(builder, n_items);
        for (i = 0; i < n_items; i++) {
                spa_pod_builder_string(builder, dict->items[i].key);
                spa_pod_builder_string(builder, dict->items[i].value);
        }
        spa_pod_builder_pop(builder, &f);
}
 
SPA_API_TAG_UTILS struct spa_pod *
spa_tag_build_end(struct spa_pod_builder *builder, struct spa_pod_frame *f)
{
        return (struct spa_pod*)spa_pod_builder_pop(builder, f);
}
 
#ifdef __cplusplus
}  /* extern "C" */
#endif
 
#endif /* SPA_PARAM_TAG_UTILS_H */